SNPs within CHRNA5-A3-B4 and CYP2A6/B6 are associated with smoking dependence but not with tobacco dependence treatment outcomes in the Czech population.
Indeed, genetic variation in the CHRNA5-CHRNA3-CHRNB4 gene cluster, encoding the α5, α3, and β4 nAChR subunits, respectively, has been shown to increase vulnerability to tobacco dependence and smoking-associated diseases including lung cancer.
Recent human genetic studies also imply that tobacco dependence is affected by polymorphisms in the alpha3/alpha5 subunits of the nAChR (CHRNA3/CHRNA5) gene cluster.